7/8 and 3/4 oz light loads are commercially available for the 20ga, and you can pick any of several powder/shell/primer/wad combos to work up your own. I am used to shooting 1200fps shells, so you might consider what you are used to shooting if the new shells speeds are slower, as speed can effect your lead especially on stations 3-6. If by light you mean lighter recoil, you can drop the shot weight to make the shell you want as light as you want, based on the published recipes ofcourse. Rick